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comparison Implab/Components/LazyAndWeak.cs @ 180:c32688129f14 ref20160224

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refactoring complete, JSONParser rewritten
author cin
date Thu, 24 Mar 2016 02:30:46 +0300
parents d5c5db0335ee
children 76e8f2ba12b8
comparison
equal deleted inserted replaced
179:478ef706906a 180:c32688129f14
1 using System; 1 using System;
2 using System.Threading; 2 using System.Threading;
3 3
4 namespace Implab.Components { 4 namespace Implab.Components {
5 /// <summary>
6 /// Creates an instace on-demand and allows it to be garbage collected.
7 /// </summary>
8 /// <remarks>
9 /// Usefull when dealing with memory-intensive objects which are frequently used.
10 /// This class is similar to <see cref="ObjectPool{T}"/> except is a singleton.
11 /// </remarks>
5 public class LazyAndWeak<T> where T : class { 12 public class LazyAndWeak<T> where T : class {
6 13
7 readonly Func<T> m_factory; 14 readonly Func<T> m_factory;
8 readonly object m_lock; 15 readonly object m_lock;
9 WeakReference m_reference; 16 WeakReference m_reference;
33 value = m_factory(); 40 value = m_factory();
34 41
35 if (Interlocked.CompareExchange(ref m_reference, new WeakReference(value), weak) == weak) 42 if (Interlocked.CompareExchange(ref m_reference, new WeakReference(value), weak) == weak)
36 return value; 43 return value;
37 } else { 44 } else {
45 lock (m_lock) {
46 // double check
47 if (weak != null) {
48 value = weak.Target as T;
49 if (value != null)
50 return value;
51 }
52 // we are safe to write
53 value = m_factory();
54 m_reference = new WeakReference(value);
55 return value;
56 }
38 } 57 }
39 } 58 }
40 } 59 }
41 } 60 }
42 } 61 }